PURPOSE: Dual-tasking refers to concurrent performance of two physical or mental tasks. Considering the critical role of dual-tasking in daily life, it is important to develop interventions to improve its efficiency or slow down its decline with age or disease. The specific purpose of this research was to study the effects of single bouts of a moderate-intensity (MI) or high-intensity interval training (HIIT) exercise on the efficiency of the extended cognitive Timed Up and Go (ETUGcog) test, which involves concurrent performance of physical and mental tasks.
METHODS: 17 males and females aged 23-35 years underwent two different single bouts of exercise sessions, a HIIT and a MI, on separate occasions, based on established protocols. Each session began with ETUGcog prior to exercise as pre-test. ETUGcog involves simultaneous performance of an extended version of Timed Up & Go test (the physical task), while counting backwards by sevens starting from a given number (the mental task). The post-tests were administered immediately after the exercise when the subject cooled down to 10% above resting HR (10%HR), and 24 hours later. The test parameters that were recorded are the number of correct responses while counting backwards until test completion, and time to complete test.
RESULTS: Correct responses after a HIIT session were significantly higher than pre-test responses when tested at 10%HR (5.18 + 1.43 vs 4.24 + 1.82, p=0.02), and 24 hours later (5.82 + 2.24 vs 4.24 + 1.82, p=0.002). No such improvements were seen after a MI session, as correct post-test responses at 10%HR (5.18 + 2.98) and 24 hours later (5.06 + 2.75) were similar to pre-test responses (4.79 + 2.47), with p>0.05 in both paired comparisons. Also, the times to complete ETUGcog tests were not significantly different when comparing the pre-test to both post-test times, with p>0.05, in both types of exercise sessions.
CONCLUSIONS: A single bout of high-intensity, but not moderate intensity exercise, might improve dual-tasking efficiency by increasing cognitive processing speeds, without delaying activity completion times, and improvements can last a full day. This could be due to neuroplastic improvements in brain’s cognitive areas in the prefrontal cortex, caused by blood flow increases sufficient with high intensity, but not with lower intensity exercise.